By Tom Neltner

The U.S. Food and Drug Administration (FDA) rejected a petition Thursday to ban perchlorate from our food, a chemical known to impair brain development in infants.

While best known as a rocket fuel component, perchlorate is approved for use in packaging for dry food such as baby rice cereal, flour and spices. Unfortunately, it also winds up in the food we eat.

Since the FDA approved the use in 2005, the amount of perchlorate that infants and toddlers ingest has increased significantly and more types of food have become contaminated. The use may have contributed to today’s high levels of perchlorate in infant rice cereal—often the first solid food infants eat.